The disclosure relates generally to the field of motion tracking, and more specifically to systems, devices, and methods for tracking and compensating for patient motion during a medical imaging scan.
There are various modalities for performing medical imaging of patients. For example, magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to visualize internal structures of the body in detail. An MRI scanner is a device in which the patient or a portion of the patient's body is positioned within a powerful magnet where a magnetic field is used to align the magnetization of some atomic nuclei (usually hydrogen nuclei—protons) and radio frequency magnetic fields are applied to systematically alter the alignment of this magnetization. This causes the nuclei to produce a rotating magnetic field detectable by the scanner and this information is recorded to construct an image of the scanned region of the body. These scans typically take several minutes (up to about 40 minutes in some scanners) and in prior art devices any significant movement can ruin the images and require the scan to be repeated.
U.S. Pat. No. 8,121,361, issued Feb. 21, 2012, entitled Motion Tracking System for Real Time Adaptive Imaging and Spectroscopy, describes a system that adaptively compensates for subject motion, and the disclosure therein is hereby incorporated herein by reference.
Additionally, there are various radiation therapies, proton therapies, and other therapies that can be applied to patients. For example, radiation therapy can be applied to a targeted tissue region. In some systems, radiation therapy can be dynamically applied in response to patient movements. However, in many such systems, the tracking of patient movements does not have a high degree of accuracy. Accordingly, the use of such systems can result in the application of radiation therapy to non-targeted tissue regions, thereby unintentionally harming healthy tissue while intentionally affecting diseased tissue. The foregoing is also true for proton therapies and other therapies.